bnx2x: Replace custom scnprintf()

Use scnprintf() when printing version instead of custom open coded variants.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>